强夯法在处理湿陷性黄土中的研究

从工程应用出发,阐述了强夯法在处理湿陷性黄土地基的加固机理以及强夯技术在处理黄土地基中的有效加固深度、夯击能等的确定,并对夯点的布置、夯击遍数和间歇时间和夯击加载机具的选择进行了介绍.     

Terrestrial isopods and myriapods in a forested scree slope: subterranean biodiversity,depth gradient and annual dynamics

Diversity, depth distribution and seasonal activity of isopods and myriapods were studied using subterranean traps buried in a forested limestone scree slope in the ?ierna Hora Mts, Western Carpathians, Slovakia, throughout the depth gradient from 5 to 95 cm. A total of five isopod, 13 diplopod and 11 chilopod species were identified. Most edaphic species strongly preferred the uppermost organic soil layers. Among the species captured, some represented rare stenoecous Carpathian endemics, namely the isopod Trichoniscus carpaticus, and diplopods Julus curvicornis and Leptoiulus mariae. Others were subterranean forms, partly adapted to hypogean conditions: the isopod Mesoniscus graniger, and diplopods Mecogonopodium carpathicum and Trachysphaera costata. The annual activity in the vast majority of the species ceased completely in winter, and was gradually relaunched in spring. In evaluating the age structure of two predominant diplopods Polydesmus denticulatus and Mecogonopodium carpathicum, both widespread across the depth gradient, a vertical segregation of early post-embryonic stages was found. While P. denticulatus tended to undergo the early stages of development in the soil-filled topmost levels, the early juvenile stage of M. carpathicum was distributed deep in the scree slope profile.     

激光诱导残余应力的试验

对激光诱导残余应力的机理进行了分析研究.用波长1.06μm、脉宽23 ns、功率密度108~109W/cm2的脉冲激光冲击外形尺寸为30 mm×30 mm×5.5 mm的LY12CZ试样,研究了激光能量密度和冲击次数对残余应力分布的影响,并将激光诱导的残余应力与传统的机械喷丸形成的残余应力进行比较.结果表明:残余压应力随着激光能量密度的加大而加大,残余压应力层的深度随着冲击次数的增加而增加,激光诱导的残余压应力层的深度是传统机械喷丸形成的3~4倍.     

A Time‐Simultaneous Prediction Box for a Multivariate Time Series

A sample‐based method in Kolsrud (Journal of Forecasting 2007; 26 (3): 171–188) for the construction of a time‐simultaneous prediction band for a univariate time series is extended to produce a variable‐ and time‐simultaneous prediction box for a multivariate time series. A measure of distance based on the L_∞ ‐norm is applied to a learning sample of multivariate time trajectories, which can be mean‐ and/or variance‐nonstationary. Based on the ranking of distances to the centre of the sample, a subsample of the most central multivariate trajectories is selected. A prediction box is constructed by circumscribing the subsample with a hyperrectangle. The fraction of central trajectories selected into the subsample can be calibrated by bootstrap such that the expected coverage of the box equals a prescribed nominal level. The method is related to the concept of data depth, and thence modified to increase coverage. Applications to simulated and empirical data illustrate the method, which is also compared to several other methods in the literature adapted to the multivariate setting. Copyright © 2015 John Wiley & Sons, Ltd.     

乌苏里江水深遥感反演

文中在分析卫星遥感测深机理的基础上,利用SVCHR-1024高光谱成像仪确定了可见光反演水深的最佳波段,通过对HJ星CCD数据各波段反射率、波段比值组合对水体、水深的敏感性分析,建立了适合于乌苏里江的单波段对数水深反演模型,从而快速获取乌苏里江河道地形信息,并探测了河道深泓线,整体精度达到80%以上.遥感反演水深可快速探测河道深泓线的方法,为乌苏里江河势演变研究提供了新的思路.     

机器学习模型在地下水埋深模拟中的适应性分析

基于京津冀气象、社会资料及地下水埋深数据,构建支持向量机(SVM)、循环神经网络(RNN)和长短期记忆神经网络(LSTM)模型对京津冀地区13个城市地下水埋深进行了模拟,并以确定系数、均方根误差、平均绝对百分比误差、纳什系数对3个模型的适应性进行了评价。结果表明：LSTM模型模拟效果最好,其次是RNN,SVM最差;不同城市基于LSTM模型进行地下水埋深模拟时参数调整最少,适应性最好,SVM模型参数调整最多。将3个模型应用于随机选择的6个测站进行验证,在华北地区浅层地下水埋深模拟方面,LSTM模型模拟精度和可信度最好,适应性最强,是该地区地下水埋深模拟的首选机器学习模型。     

时变流动性深度模型

使用超高频数据,并利用流动性深度指标,研究流动性的动态特征、影响因素以及检验市场微观结构理论.结果支持基于信息不对称下的市场微观结构理论.研究还表明耐心交易可以降低交易成本.     

考虑流体影响的水轮机叶轮固有频率

将工作时水轮机叶轮简化为浸在流体中的旋转圆盘,建立了流体中圆盘振动微分方程,并考虑边界条件对其固有频率的影响.分别研究了不同圆盘转速、不同流体深度以及不同流体密度对固有频率的影响.研究结果表明,与真空中圆盘的固有频率相比,沉浸在流体中的圆盘的固有频率降低.当浸在流体中的圆盘发生旋转时,圆盘的模态由驻波变为行波,不同的旋转方向将对应两个不同的固有频率值.当流体深度减小时,固有频率值降低;流体密度越大,固有频率越小.     

浅谈如何开展档案知识下乡活动

档案不仅具有再现历史背景的作用,而且对现实社会具有考查凭证作用。论述了开展档案知识下乡活动的必要性和档案知识下乡对社会的影响,提出了开展档案知识下乡活动的具体做法。     

基于CDIO理念的五级层进式人才培养模式研究——以高职国际商务专业为例

CDIO成为近年来指导高等院校教学改革实施的指导思想,为满足区域经济特点和行业企业需求的国际商务专业人才的培养,需要设计人才培养体系和人才培养方案。基于CDIO理念的人才培养模式的设计和培养思路的建立,将成为培养国际商务专业高技能复合型人才的实施途径。